Sir: Andrew Hamilton (letter, 24 May) writes of the high level of pollution from crop spraying. At this time of the year I pick elderflowers to make elderflower cordial, much liked by members of the Cambridge University Real Tennis Club. I am never sure whether I ought to pick the flowers from bushes along the road and thereby subject to lead-poisoning, or from bushes on the borders of fields which are subject to some very powerful chemical cocktails. Which is going to be worse?
Swaffham Bulbeck, Cambridgeshire